This disclosure is related to the feeding of media sheets in a printer or copier and more particularly to detecting and preventing multifeeds of sheets.
Multifeeds of media sheets in a printer or copier can be typically caused by welding of sheet edges, porosity of sheets, adhesion and static charge between sheets, as well as separate sheets being fed from multiple feed trays. A vacuum sheet feeding system can reduce some but not all multifeeds of sheets. When multifeeds do occur, the multiple sheets can jam the printer or copier forcing an operator to fix the jam, intervene with the print job, and possibly even damaging the printer or copier.
Quite often the multifeed will manifest itself as a “shingle” multifeed. In this case, the multifed sheets are not exactly overlapped and will have an offset. Due to the overlap, it is possible to separate the sheets by holding the trailing sheet in the previous set of nips and allowing the leading sheet to be taken away.
The present disclosure provides for an apparatus and method to detect and separate shingle sheets and thereby reduce multifeed/jam rates.